Elma, the eldest son of a noble house of swordsmen, is branded a nobody and exiled from his family for reviving the "Heavy Knight" class, considered by all to be the worst and most useless of all. But there's one small detail that everyone ignores: this fantasy world is identical to the role-playing video game to which Elma dedicated her entire life in her previous existence. She knows every glitch, damage calculation formula, hidden ability, and trick for gaining experience at lightning speed by heart. Aware that the Heavy Knight actually possesses the most devastating defensive stats and counterattack combos in the game when used properly, Elma begins to undermine the system from within. Between clearing deadly dungeons alone, building crazy builds that disintegrate giant monsters, and conquering legendary gear that others thought was junk, our protagonist takes bloody revenge on those who underestimated him, climbing the ranks of the hunters through ruthless strategy and outsized numbers.